In JB it was possible via XPosed + Gravitybox to disable these tones.
In Gravitybox for KitKat the option is there under Media Tweaks : "Mute Volume adjust sound"
(disable sound played when adjusting volume using volume keys)
But it does not work

Since Gravitybox is for AOSP Roms, maybe i don't have a point filing in bug for gravitybox (KitKat version)

Does someone have a tip or idea how to disable these tones otherwise ?
This is not a sound in /system/media/audio/ui -> that's no option
I think these sounds are in the framework.
I found a possible solution here, but this compiling thing is not my cup of tea ...

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